Retrospective Analysis of Pyrotinib-Based Therapy for Metastatic Breast Cancer: Promising Efficacy in Combination with Trastuzumab

Abstract

Purpose

To evaluate the efficacy and safety of a pyrotinib-based therapy for human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) in the real world.

Methods

Clinical data of 218 patients with HER2-positive MBC who received a pyrotinib-based therapy from January 2020 to March 2023 at the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed.

Results

Finally, 195 patients were included in the efficacy cohort. The median progression-free survival (PFS) in the total population is 12.4 months (95% CI, 9.8–15.0 months). More than half of the patients in the efficacy cohort received pyrotinib mono-targeted therapy (103 cases, 52.8%). Among the remaining patients, 74 (37.9%) patients chose a combined trastuzumab-targeted therapy and 17 (8.7%) chose to combine inetetamab. Median PFS in the pyrotinib group vs pyrotinib plus trastuzumab group was 10.5 months vs 20.1 months (P<0.001). The median PFS of primary trastuzumab resistance population reached to 20.1 months in pyrotinib plus trastuzumab group. Double-targets’ advantage was also observed in the brain metastases subgroup (17.9 months vs 10.0 months, P=0.386). The patients who received pyrotinib plus inetetamab as second and higher-line treatment reached a median PFS of 7.9 months (95% CI, 4.0–11.8 months). Forty-one (19.8%) of 207 patients included in the safety cohort experienced grade 3 or higher diarrhea, the most common adverse event in safety analysis, and no adverse event-related deaths.

Conclusion

The combination of pyrotinib and trastuzumab demonstrated promising efficacy in the treatment of HER2-positive metastatic breast cancer, including those who had primary resistance to trastuzumab and brain metastases. Pyrotinib plus trastuzumab is expected to be a potent option in the first-line. Additionally, the concurrent administration of pyrotinib and inetetamab could be an alternative to consider in the second and higher-line treatment for metastatic breast cancer. The adverse reactions of pyrotinib were tolerable in general.

Keywords:

• pyrotinib
• HER2
• metastatic breast cancer
• trastuzumab
• inetetamab

Data Confidentiality Statement

The data of patients included in our study was anonymized and properly protected, including encrypted storage of patient information, strict control of access, and timely destruction of unnecessary information.

Data Sharing Statement

The data of this study could be obtained from the corresponding author upon reasonable request.

Ethics Approval and Informed Consent

All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and national research committee and the 1964 Helsinki Declaration and its later amendments. The ethics approval was obtained from Ethics Committee of The First Affiliated Hospital of Zhengzhou University (2023-KY-0814-001). According to the national legislation and the institutional requirements, written informed consent was waived in this retrospective study.

Author Contributions

All authors contributed to the study’s conception and design. Data analysis was performed by QG, YW, and MZ. The first draft of the manuscript was written by QG and all authors contributed to revising the article, have agreed on the journal to which the article will be submitted, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that they have no competing interests.

Additional information

Funding

This research was supported by the 2020 Medical Science and Technology Project of Henan Province, China (Grant No. LHGJ20200293); Chinese Society of Clinical Oncology (CSCO) Research Foundation in Beijing (Y-JS2019-016).